Start by making the pancakes. Beat the eggs with a whisk in a suitable bowl, add the sugar, salt and vanilla, stir. Add the flour and gradually pour in the milk and melted butter.
You have to get a homogeneous mixture. From it, fry thin pancakes in an oiled pan. You can make the pancakes with just water but they won't be nearly as delicious. From the quantities listed you'll get about 20 pancakes.
Boil the milk for the cream with the sugar. Combine the egg yolks with the starch, 2 tbsp water and the vanilla. Pour in the milk little by little and return the mixture to the stove. Boil until thickened.
Once the cream is ready, transfer it to a bowl and add the butter and crumbled chocolate to it. Stir and leave it to cool. Smear the pancakes with the cooled cream and arrange them on top of one another.
If you like, you can assemble the cake in a form. Leave it to harden in the fridge for 4 hours. Pour melted chocolate, with a little oil for shine, over the ready cake.